Yankees-Red Sox out of baseline

[rs1128]

On first viewing, it looked like her came too far off line and I felt the runner should have been called out and was not surprised that the call was reversed. But the more I see it the more I'm not so sure.

I might have the rule completely misinterpreted, but I thought the runner is out if he veers more than 3-feet from from wherever the tag is attempted. He appears to be on the base line and base path all the way to the point where A-Rod is positioned. Then he veers, but never more than 3-feet, again from what I can tell. He moves off the line (and path) after the tag is attempted, as his momentum carried him that way, but is within 3-feet before the attempt and at the point of attempt.

So was the initial call right?